Write the reaction when solid lead(ii) nitrate is put into water:

Calculate the pH of a solution that contains 2.7 M HF and 2.7 M HOC6H5. Also, calculate the concentration of OC6H5- in this solu

borishaifa [10]

Answer:

$\large \boxed{\mathbf{1.36; 3.6 \times 10^{\mathbf{-9}}}\textbf{mol/L}}$

Explanation:

The HF is about five million times as strong as phenol, so it will be by far the major contributor of hydronium ions. We can ignore the contribution from the phenol.

1 .Calculate the hydronium ion concentration

We can use an ICE table to organize the calculations.

HF + H₂O ⇌ H₃O⁺ + F⁻

I/mol·L⁻¹: 2.7 0 0

C/mol·L⁻¹: -x +x +x

E/mol·L⁻¹: 2.7 - x x x

$K_{\text{a}} = \dfrac{\text{[H}_{3}\text{O}^{+}] \text{F}^{-}]} {\text{[HF]}} = 7.2 \times 10^{-4}\\\\\dfrac{x^{2}}{2.7 - x} = 7.2 \times 10^{-4}\\\\\text{Check for negligibility of }x\\\\\dfrac{2.7}{7.2 \times 10^{-4}} = 4000 > 400\\\\\therefore x \ll 2.7\\\dfrac{x^{2}}{2.7} = 7.2 \times 10^{-4}\\\\x^{2} = 2.7 \times 7.2 \times 10^{-4} = 1.94 \times 10^{-3}\\x = 0.0441\\\text{[H$_{3}$O$^{+}$]}= \text{x mol$\cdot$L$^{-1}$} = \text{0.0441 mol$\cdot$L$^{-1}$}$

2. Calculate the pH

$\text{pH} = -\log{\rm[H_{3}O^{+}]} = -\log{0.0441} = \large \boxed{\mathbf{1.36}}$

3. Calculate [C₆H₅O⁻]

C₆H₅OH + H₂O ⇌ C₆H₅O⁻ + H₃O⁺

2.7 x 0.0441

$K_{\text{a}} = \dfrac{0.0441x} {2.7} = 1.6 \times 10^{-10}\\\\0.0441x = 1.6 \times 10^{-10}\\x = \dfrac{1.6 \times 10^{-10}}{0.0441} = \mathbf{3.6 \times 10^{\mathbf{-9}}}\textbf{ mol/L}\\\text{The concentration of phenoxide ion is $\large \boxed{\mathbf{3.6 \times 10^{\mathbf{-9}}}\textbf{ mol/L}}$}$

6 0

3 years ago

The student is now told that the four solids, in no particular order, are aluminum chloride (AlCl3), sugar (C6H12O6), benzoic ac

zaharov [31]

Answer:

AlCl₃, NaBr, C₆H₅COOH, C₆H₁₂O₆.

Explanation:

The more ions in solution, the greater the conductivity of a solution because these charged particles can carry electrons in the solution.

In the first place, when AlCl₃ dissolves in water it produces 4 ions:

AlCl₃(aq) ⇄ Al³⁺(aq) + 3 Cl⁻(aq)

If the solution is 0.20M in AlCl₃, it will be 4 x 0.20M = 0.80M in ions.

Secondly, NaBr is a strong electrolyte (complete ionization) so it produces 2 moles of ions per each mole of NaBr dissolved:

NaBr(aq) ⇄ Na⁺(aq) + Br⁻(aq)

If the solution is 0.20M in NaBr, it will be 2 x 0.20M = 0.40M in ions.

Then, benzoic acid is a weak electrolyte (partial ionization) so it will produce less than 2 moles of ions per each mole of benzoic acid dissolved:

C₆H₅COOH(aq) ⇄ C₆H₅COO⁻(aq) + H⁺(aq)

If the solution is 0.20M in benzoic acid, the solution will be far below 0.40M in ions.

Finally, sugar has only nonpolar covalent bonds so it will produce no ions in solution, thus being a poor electricity conductor.

4 0

3 years ago

How many grams of barium sulfate form when 35.0 ml of 0.160 m barium chloride reacts with 58.0 ml of 0.065 m sodium sulfate? do

vazorg [7]

Barium sulfate weighs 0.88 grams per gram.

Mass:

A physical body's overall composition is measured by its mass.

Inertia, or the body's resistance to acceleration in the presence of a net force, is also measured by it.

The mass of a thing also affects how strongly it attracts other bodies through gravity.

In the SI, the kilogram serves as the basic mass unit (kg).

This information

Moles of BaCl2 equal 5.6 x 103 (35 x 0.160 / 1000)

sodium sulfate moles equal 58 x 0.065, or 3.77 x 103,

Na2SO4 with BaCl2 ——————————-> 2NaCl plus BaSO4

Na2SO4 is the limiting agent here.

Therefore, the product relies on limiting reagent.

1 mol of Na2SO4 produces 1 mol of BaSO4.

0.00377 moles of BaSO4 is one mole.

moles = mass / molar mass of BaSO4.

0.00377 = mass / 233.4

BaSO4 mass is 0.88 g.

So, 0.88 grams of barium sulfate make up one gram.

To know more about the mass visit:

brainly.com/question/28204586

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3 0

1 year ago

What are the 7 methods of separating mixtures?

Gennadij [26K]

Methods Of Separating Mixtures

Handpicking.

Threshing.

Winnowing.

Sieving.

Evaporation.

Distillation.

Filtration or Sedimentation.

Separating Funnel.

3 0

3 years ago

Read 2 more answers

Before we can use this equation for

AlexFokin [52]

Answer:

2C₂H₆ + [7]O₂ → [4]CO₂ + [6]H₂O

Explanation:

Chemical equation:

C₂H₆ + O₂ → CO₂ + H₂O

Balanced chemical equation:

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

Step 1:

2C₂H₆ + O₂ → CO₂ + H₂O

Left hand side Right hand side

C = 4 C = 1

H = 12 H = 2

O = 2 O = 3

Step 2:

2C₂H₆ + O₂ → 4CO₂ + H₂O

Left hand side Right hand side

C = 4 C = 4

H = 12 H = 2

O = 2 O = 9

Step 3:

2C₂H₆ + O₂ → 4CO₂ + 6H₂O

Left hand side Right hand side

C = 4 C = 4

H = 12 H = 12

O = 2 O = 14

Step 4:

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

Left hand side Right hand side

C = 4 C = 4

H = 12 H = 12

O = 14 O = 14

3 0

2 years ago